This invention relates to a tool holder device for holding a double-ended tool bit, for example a tool bit having a screw-engageable end and a drill end, especially for use in hand tools having bit holders and exchangeable bit tools.
In a first embodiment of the invention the holder comprises:
an elongated connector means having a first end and a second end, where the elongated connector means has a central longitudinal hole, of a cross-section corresponding to a cross-section of a mounting portion of the tool bit, at the first end, and a tool mount at the second end,
a first sleeve arranged to reciprocally slide over the connector means between a first end position and a second end position, the first sleeve having a third end facing the tool bit and a fourth end facing the hand tool.
The connector means has a substantially cylindrical tubular first collar arranged on the connector means adjacent the first end, the first collar having an inner diameter which is cooperating with an outside diameter of the connector means, to allow the first collar to rotate on the connector means, the first collar further having a first recess to hold a first locking ball, and a second recess and a third recess arranged on an outer surface of the connector means adjacent the first end, the first locking ball being movable between the second recess and the third recess by rotation of the first collar, and the first locking ball being held in the first recess during rotation of the first collar, so that the first locking ball is seatable into either of the second or third recesses, the first collar further having a fourth recess for holding a substantially cylindrical pin, which pin rotates together with the first collar, a part of the pin reaching out into a slot arranged in the connecting means, the slot and the pin being located so that, when the first locking ball is seated in the second recess, the pin is at one extreme of the slot, and when the first locking ball is seated in the third recess, the pin is located at the other extreme. Retention of the tool bit is enabled by offsetting the hex opening in the first collar to engage the slot in the bit.
Advantageously, the connector means has a first circumferential groove adjacent the second end cooperating with a retaining ring mountable in the first circumferential groove, and an outwards facing annular ridge arranged adjacent the first end. The first sleeve has an inwards facing annular ridge arranged at the fourth end of the first sleeve, so that the inwards facing annular ridge and the outwards facing annular ridge cooperate to prevent the first sleeve from sliding off the connector means in a direction towards the first end to define the first end position, and the retaining ring and the inwards facing annular groove cooperate to prevent the first sleeve from sliding off the connector means in a direction towards the second end to define the second end position.
A further embodiment of a holder for holding a reversible tool bit/drill bit according to the invention comprises:
an elongated connector means having a second sunken recess, which is a portion of the connector means having a smaller outer diameter than a largest outer diameter of the connector means, the second recess further having a third step and a fourth step, the third and fourth steps together with a surface of the second recess defining a substantially tubular space in which a third, substantially cylindrical collar is slidingly arranged, the third collar having an axial slit running the entire length of the third collar, and the second recess further having a third radial hole and the third collar having a fourth radial hole, arranged to cooperate with a third locking ball, so that the third locking ball is prevented to fall out of the third collar when the third collar is assembled over the third locking ball onto the connector means and so that the third locking ball is prevented from passing through the third radial hole, the third locking ball serving as a stop in a corresponding groove in the tool bit, to hold the tool bit in place after insertion into the connector means.
Preferably, the connector means further comprises a fourth circumferential groove, arranged adjacent a second end of the connector means, and a fifth circumferential groove, arranged adjacent a first end of the connector means, and wherein a second sleeve is arranged to reciprocally slide over the connector means between two end positions, the connector means having an axial hole with a large diameter portion adjacent the first end of the connector means, and a small diameter portion running a substantial length of the connector means, and wherein a fifth step connects the large diameter portion and the small diameter portion of the axial hole, so that the second sleeve is extendible to stabilize a screw during an actual screw-driving operation, when the tool bit is held in the large diameter portion by abutting the fifth step, and by the third locking ball which engages the groove of the tool bit.
Advantageously, the connecting means has a first sunken recess arranged at the first end, the first recess having a first step, adjacent the first end, and a second step, facing away from the first end, the first and second steps together with a surface of the first recess defining a substantially tubular space in which a substantially cylindrical second collar is slidingly arranged, the second collar having an axial slit running the entire length of the second collar, the first recess further having a first radial hole and the second collar having a second radial hole, arranged to cooperate with a second locking ball, the second locking ball protruding a sufficient amount through the first radial hole, when the holder is assembled, to serve as a stop for the second sleeve in either the first circumferential groove or the second circumferential groove.
A reversible drill bit/screw bit tool, for use with a tool holder according to the invention, preferably comprises a hex portion at one end of the tool, and a drill portion at an opposite end of the tool, and where the hex portion has a screw driving end, shaped for engagement with a screw head, and a sixth circumferential groove and a seventh circumferential groove, for cooperation with a third locking ball of a connecting means of the holder.
According to the invention, a combination drill stop/counter sink means comprises:
a stop end,
a counter sink end,
a longitudinally centered through hole, which has an inner diameter corresponding to an outer diameter of a drill,
a threaded radial stop screw hole in which a stop screw is lodged, the combination drill stop/counter sink means being slidable over the drill portion and securable at a desired drill depth by tightening the stop screw to abut the drill portion,
a stop surface arranged perpendicularly to the through hole at the stop end, and cutting means arranged at the counter sink end.